oddly enough, I've had them just about exactly one year. Back on Memorial day (this year) was the first time I had an idle low problem, even stalling. I cleaned the IAC, and that seemed to fix it, for 3-4 weeks. Then it started happening again, so I began looking for codes, got one each for front and rear o2 sensor, both lean. That struck me as odd, because as memory serves me, the XIEDs were supposed to bring the mixture level from 14.6 to about 13.8. Funny thing was, I remeber when i got them, I talked to Nightrider and asked how I would know if they ever went out on me. the man told me that once put on the bike, they could be taken off and the bike would run the same, ie: the system had already been fooled. Only time, he said, when the bike would need to know they were there was during a battery change, which I have not done.
I'm goning to get a hold of them right now, I'll post back.